• Advances in nano research
• /
• 제7권1호
• /
• pp.1-11
• /
• 2019

In this article, wave propagation characteristics in magneto-electro-elastic (MEE) nanotube considering shell model is studied in the framework nonlocal theory. To account for the small-scale effects, the Eringen's nonlocal elasticity theory of is applied. Nonlocal governing equations of MEE nanotube have been derived utilizing Hamilton's principle. The results of this investigation have been accredited by comparing them of previous studies. An analytical solution of governing equations is used to obtain phase velocities and wave frequencies. The influences of different parameters, such as different mode, nonlocal parameter, length parameter, geometry, magnetic field and electric field on wave propagation responses of MEE nanotube are expressed in detail.

• 디지털산업정보학회논문지
• /
• 제11권3호
• /
• pp.179-200
• /
• 2015

Recent national policies National Competency Standards(NCS) to develop teaching-oriented education in the field of industry and learning is taking place. Plan to take advantage of the Internet and multimedia classes, information and communication technology (ICT) for ways to leverage the integration appearing in various forms. The purpose of this study is causal influence on the ARCS motivation theory can determine the basic psychology of human motivation factors and the desires of a typical human nature theory dealing with the psychological needs of interactivity and immersion is learning achievement and learning transfer and to validate the demonstration. By applying information and communication technology sector in the development of learning in information and communication equipment training program modules from a field study conducted at the NCS with a clear empirical and empirical research through the synchronization to the learner and to explore the possibility of generalization.

• International journal of advanced smart convergence
• /
• 제10권3호
• /
• pp.245-256
• /
• 2021

This study is significant in determining the reduction of safety accidents by applying PDCA's theory by subdividing it into a case analysis technique for construction sites by PDCA's theory. For this study, accidents accounted for the largest proportion of each type of disaster in the construction site were considered, and safety accidents were reduced through the PDCA theory through prior research. The analysis method of this study derived improvement plans by applying PDCA techniques to plan, implement, confirm, review, and improve disaster accidents at construction sites. The conclusions of this study are as follows. In the plan, first of all, measures shall be taken to prepare a safety management plan, to verify the implementation of the plan, and to verify the degree of implementation by the field manager. In the implementation, first of all, it is necessary to introduce a safety education history system to strengthen the safety education curriculum to suit the site, as long-term work is impossible for field workers depending on field conditions. First of all, it is necessary to strengthen the installation of safety facilities, including "work scaffolding" and "conducting prevention facilities" at construction sites. In management review and improvement, the risk assessment system for construction sites needs to be expanded first°.

• 대한한의진단학회지
• /
• 제19권1호
• /
• pp.55-63
• /
• 2015

Objectives In order to the review of the Yoon Gil-Young's theory on the "differentiation of syndromes", we studied on the his method and system of classification on the "differentiation of syndromes". Methods We reviewed on "The Clinical Formula Science Traditional Korean Medicine 東醫臨床方劑學", "A study on the Methodology of Traditional Korean Medicine 東醫學의 方法論硏究" "The theory of SaSang Constitution Medicine 四象體質醫學論". From a connected standpoint with the basic theory and clinical medicine, considered on the Yoon Gil-Young's theory of "differentiation of syndromes". Results Yoon Gil-Young's theory of differentiation of syndromes and treatment was widespread so much that he studied on the learning field of Traditional Korean Mediciine and ingenious as well. The main principles of differentiation of syndromes was summarized the three representative syndrome-complexes; BON-HER(original deficiency syndrome), BON-HAN(orginal cold excess syndrome), BON-YEOL(original heat excess syndrome). And also the three representative syndrome-complexes was previously carried out the details of differentiation of syndromes and assigned represent prescription one by one. Conclusions As the results, Yoon Gil-Young insisted the system of differentiation of syndromes closely connecting with Traditional Korean Medical physiology, pathology, diagnosis and prescriptions. And therefore he was a frontier of the field of Traditional Korean Medicine.

• Advances in nano research
• /
• 제11권6호
• /
• pp.581-593
• /
• 2021

This model is proposed to describe the buckling behavior of Carbon Nanotubes (CNTs) embedded in an elastic medium taking into account the combined effects of the magnetic field, the temperature, the nonlocal parameter, the number of walls. Using Eringen's nonlocal elasticity theory, thin cylindrical shell theory and Van der Waal force (VdW) interactions, we develop a system of partial differential equations governing the buckling response of CNTs embedded on Winkler, Pasternak, and Kerr foundations in a thermal-magnetic environment. The pre-buckling stresses are obtained by applying airy's stress function and an adjacent equilibrium criterion. To estimate the nonlocal critical buckling load of CNTs under the simultaneous effects of the magnetic field, the temperature change, and the number of walls, an optimization technique is proposed. Furthermore, analytical formulas are developed to obtain the buckling behavior of SWCNTs embedded in an elastic medium without taking into account the effects of the nonlocal parameter. These formulas take into account VdW interactions between adjacent tubes and the effect of terms involving differences in tube radii generally neglected in the derived expressions of the critical buckling load published in the literature. Most scientific research on modeling the effects of magnetic fields is based on beam theories, this motivation pushes me to develop a cylindrical shell model for studying the effect of the magnetic field on the static behavior of CNTs. The results show that the magnetic field has significant effects on the static behavior of CNTs and can lead to slow buckling. On the other hand, thermal effects reduce the critical buckling load. The findings in this work can help us design of CNTs for various applications (e.g. structural, electrical, mechanical and biological applications) in a thermal and magnetic environment.

• 한국보건간호학회지
• /
• 제13권2호
• /
• pp.26-44
• /
• 1999

The study was done to improve the job training course for Community Health Practioners (CHPs) by evaluating the level of help that the training provided to the CHPs in carrying out their work and to analyze the management activities of the CHPs in order to develop a more effective CHP training program. The methodologies used in the study were a questionnaire survey. The survey results were analyzed using SPSS Windows. The study results are as follows. 1. The total average level of help from the job training(Theory. Practice and Field Practice) for carrying out the CHP work was found to be $3.04\pm.53$ (of a possible 4), which indicates a high level of help. The average for clinical practices was $3.16\pm.60$. for theory. $3.11\pm.40$ and for field practice. $2.84\pm.60$. 2. For the theory content of the job training courses. the help level was low in the area of mother and child health management/family planning with an average of $2.65\pm.62$ and in the area of health information system development with an average of $2.62\pm.83$. The reason for these deficiencies were. in order of frequency. few opportunities to apply learning. training content that was inadequate. training methodologies which were incongruent with content. improper training items and insufficient class hours. For the practice. the clinical work in rehabilitation/orthopedics departments and in ENT/Opthalmology departments had averages of $2.96\pm.86$ and $2.97\pm.80$ respectively. This low level resulted from the lack of direct experience. lack of sincerity during the practice time. lack of practice guidance. insufficient time and lack of practice equipment. in that order. For the field practice. the delivery management averaged $2.06\pm.90$ as the lowest help level. In this case 68% of respondents replied that there were no relevant reasons for this deficiency. 21% responsed that there was a lack of direct experience, 7%, a lack of practice guidance and 4.8%, insufficient time. 3. There were significant differences for several demographic variables when comparing the help level of the clinical courses (practice and Field Practice). A higher help level was reported by older nurses as compared to younger ones, experienced nurses as compared to scholarship nurses, and married over single. Also for nurses who had finished more other programs and were qualified or licensed in several areas the level was high. Although it was not statistically significant the level was higher if the work area was in a rural county, not a city, and if one had more recently completed the job training(P<,05). 4. Of the respondents 58.6% replies stated the period of job training for the CHP was adequate, but 51.7% reported that the period for theory courses was too short while an other 48.3% responded that it was sufficient. For practice locations, 50% responsed that it was good to practice in medical institutions(primary, secondary and tertiary) at the same time. While 48.3% agreed that doing theory and practice simultaneously was good, and 56.9% agreed that field practice should be done after completing theory and practice training. Hence, the development of new field practice guidelines suitable for changing environments of health management are required in place of the existing ones which were considered low in help level to the practical work of the CHPs.

• 한국실천공학교육학회논문지
• /
• 제2권2호
• /
• pp.55-60
• /
• 2010

평상시 전자기 현상들을 접하고 있는 우리들은 이러한 현상들의 단편적인 면은 느낄 수 있으나 시각적으로 파악하기 어려운 현상이며 더욱이 물리 및 정량적으로 이해하기란 쉬운 일이 아니다. 이들 정전기장, 정자기장 또한 전자장이 결합되어있는 교류자장은 실험식과 이론적으로 James Clerk Maxwell에 의해 1873년도에 완성되었다. 따라서 전자장은 Maxwell방정식에 근거를 둔 수식의 전개로 전기 자기 현상을 다룬다. 이러한 수식전개가 바탕이 되는 학문이기에 처음으로 전자기를 배우는 중 고등학교 학생, 대학 기본과목인 대학 물리를 배우는 대학생, 이와 관련된 전공 학생에게 조차 이해하기에 어려움이 따른다. 따라서 이러한 난점들을 해결하고자 전자기 제반현상들을 시각적으로 파악하고 더 나아가 수식적으로 해를 구하기 어려운 문제들을 수치해석방법을 이용해 해의 거동을 추정할 수 있도록 하는 학부 수준의 가상 교육용 전자장 프로그램을 개발하고자 하였다.

• 충청수학회지
• /
• 제26권1호
• /
• pp.167-174
• /
• 2013

The main goal in the present paper is to obtain a solution of Einstein's unified field equations for the third class in $X_4$.

• 대한기계학회논문집A
• /
• 제21권10호
• /
• pp.1598-1608
• /
• 1997

Based on the application of te theory of conjugate approximations and the Loubignac's iterative method in a local region, a method to improve the stress filed in a displacement-formulated finite element solution has been proposed. The validity of the proposed method has been tested through two examples : a thick cylinder under internal pressure loading and an infinite plate with a central circular hole subjected to uniaxial tension. As a result of analysis of the examples, it was found that the stress field obtained for the local region model by the proposed method approximates well for the whole domain model. In addition, it was found that because of a significant decrease in the computing time to obtain the improved stress field, the proposed method is efficient and useful for the detailed stress analysis in local regions.

• 소성∙가공
• /
• 제13권1호
• /
• pp.33-38
• /
• 2004

A new approach for the design of extrusion die surface of arbitrarily shaped section is presented. In order to generate the extrusion die surface. an automatic surface construction method based on B-spline surface and scalar field theory is proposed. The isothermal lines and stream lines designed in the scalar field are introduced to find the control points which are used in constructing B-spline surfaces. Intersected points between the isothermal lines and stream lines are used to construct B-spline surfaces. The inlet and outlet profiles are precisely described with B-spline curves by using the centripetal method for uniform parameterization. The extrusion die surface is generated by using the cubic curve interpolation in the u- and v-directions. A quantitative measure for the control of surface is suggested by introducing the tangential vectors at the inlet and outlet sections. To verify the validity and effectiveness of the proposed method, automatic surface generation is carried out for extrusion dies of arbitrarily shaped sections.